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Comment Re: Sixty Years Ago... (Score 1) 51

And they left it to Sierra Nevada to propose a space plane.

Indeed and you have supplied good examples of the craft with Dream Chaser, which is a more optimized design - thanks. I accept your's and cjameshuff's points about a space plane. I'm not arguing a capsule vs plane approach, simply commenting on the state of art in that technology. If a market emerges perhaps we will see more of them.

Yes, but their candidate for Commercial Crew is the CST-100. Which looks like a modernization and upscaling of the Apollo CM.

I have nothing against the capsule approach and have often lamented on how progressed space travel might have been had the Apollo platform been developed more. Far from arguing against the development of this type of vehicle, I'm excited that we are able to have a conversation like this and that there are three 7 crew member options available all vying for a role taking people to space.

The commercialization of space is one of the most exciting things I have seen for a while, I'm grateful for Elon Musk's efforts.

I won't be able to respond to further posts for a while as I am of to get some surgery on my spine today. Thanks for the conversation.

Comment Re: Sixty Years Ago... (Score 1) 51

We could also use risk management metrics to make the case against spaceplanes. The shuttle had too many criticality 1 components, etc.

The Shuttle had those critical components because it was a complex vehicle with launch components on it. If you are using the risk management metrics of a side by side launch configuration with engines in it, then we are not talking about the same thing.

The CAIB report pointed out that it's risk analysis of the shuttle launch configuration produced approximately 130 impacts to the heat shield per launch. That would be eliminated in a top of stack configuration. So too would the main engines making for a less complex, less massive vehicle. A space glider.

Whether you need wings is not what I am saying, I am making the observation that none of the designs we have seen implemented produced an optimal vehicle.

Perhaps Boeing knows something we don't.

Comment Re:Sixty Years Ago... (Score 1) 51

What do you need wings for?

As I said. What my OP was suggesting was that we have not seen the most optimized design for a space plane, or more specifically, a space glider. We have never implemented a low mass glider from space.

Note: "to operate from an airport" is not an answer.

To reduce ballistic forces on re-entry, to not carry volatiles for landing, to carry more than three tons of payload back to earth, to build a simpler vehicle. Perhaps to use some of the launch energy on delivering a product produced in orbit to a specific place on earth. I don't know what possible future requirements there are. Any improvement to ablative heat shield technology, as the Dragon V2 will produce, can also be applied to a space glider.

You might be right or wrong. I'm not religiously connected to the idea of having wings in space enough to care. I accept all of the reasons you point out as pretty good reasons for not having winged space vehicles, however it still doesn't change what I saying: we have not seen the most optimized design for a space vehicle of this kind, specifically a space glider. That has nothing to do with the obsolescence of a design, idea or concept, simply a statement of fact.

My other suggestion was if there is a reason to have a space glider then the emerging market economy for space products will produce one.

Thanks for the conversation, I'll be in surgery and out of action for a while.

Comment Re:Sixty Years Ago... (Score 1) 51

It's great to see the myths of non-reusable first stage technology being dispelled.

Indeed, SpaceX has thoroughly demolished the claims of SSTO fans that reuse and low cost are somehow incompatible with staging.

We agree that this is a step forwards in getting to orbit.

We don't need wings.

They are useful though.

For what?

For operating a vehicle in atmosphere, which occurs at two critical stages of a spacecraft's mission.

Spaceplanes are dead.

Does a spaceplane have to include engines?

Take Skylon as a representative example:

No. That is specifically the design I am arguing against. Please check my post again and you will see I deliberately *exclude* the mass of the engines.

Perhaps it would make more sense if I introduced the term "Space Glider" to describe what I am talking about.

assuming it lived up to expectations, Skylon

I agree, I doubt this design would have lived up to expectations and what we have seen is failed designs for a sort of spaceplane with engines. What my OP was suggesting was that we have not seen the most optimized design for a space plane, or more specifically, a space glider.

Comment Re:Sixty Years Ago... (Score 1) 51

Well, it beats making them into the world's most complicated air planes as with the space shuttle. SpaceX has proven that they can do vertical landings of the first stage intact onto both land and a seagoing barge; after a trip out of the atmosphere and to about 1/5 of orbital velocity but not into orbit.

It's great to see the myths of non-reusable first stage technology being dispelled.

That turns out to be far less expensive and complicated than a space plane. It does turn out we need a lifting body for much larger vehicles. It still doesn't have to be a plane, though.

I think you have to separate the concept from the implementation of a space plane design. SpaceX's launcher effort is less expensive and complicated than the space planes implemented so far. However both Buran and the Space Shuttle had the orbiter on the side of the stack where their heat shield was exposed to debris from the launch vehicle. So much so it was considered to be 'In-Family' because it would occur every launch to some degree.

The Space Shuttle also had all of the complexity related to the main engines which had no business being in orbit. Having the mass of those engines also complicates the infrastructure of landing. Considering also many of the political issues that interfered with the implementation of the Shuttle it wasn't the best design for a space plane.

We don't need wings.

They are useful though. The contrast is having the space plane at the top of the launcher stack, which removes the 'in-family' debris, main engine mass and, complexity issues for operating a space plane, as the X-37 demonstrates. The X-37 is covered by a shroud, however having some control surfaces at the top of a launch stack for a larger vehicle could be useful considering launchers have control surfaces near the base to balance it. A less massive orbiter means more for vehicle and payload reaching orbit and returning.

Musk has taken the pork barrelling out of launcher design and shown that it is possible to recover launcher assets. That knowledge maybe the foundation of opening up commercial space ventures paving the way for more commercial launcher platforms to become available.

The good thing about commercialization could mean someone implementing a space plane with a better design or more specific role. With those things in mind maybe we haven't seen the most optimal design for a space plane yet.

Comment Re:Honest Question (Score 4, Insightful) 151

I think the most important usability features X11 has over Windows and mac is the suberbly powerful cut paste and remote display paradigm. If I can use those X features in Wayland I'll be happy, otherwise, I think you have a point Mr AC.

I switched from Windows to linux because I was sick of that shit, change for change sake. I want change for the sake of a usability improvment in a computing interface that I am compelled to use because it makes me more efficient at using a computer. I am an advanced user and I want an advanced interface. For me that is an ambidextrous mousing paradigm, remote windows, more advanced cut and paste, multiple desktops.

Frankly, UI configurability in linux has gone backwards since it got more popular, workspaces interfaces have *less* functionality than it did in 2008 when I could drag windows between workspaces and you could configure just about every aspect of gnome to customize your linux desktop experience. I didn't want a Mac or Windows UI and since their UI's adopted workspaces the functionality in linux seems to be dumbed down and advanced linux GUI features being domesticated.

Wayland looks like it is answering the need for backwards X11 compatibility with Weston so it remains to be seen if it will take the powerful features of X11 and leave some of the atropied aspects behind.

Comment Re:Wayland bashing (Score 1) 151

wayland initially was infested by the type of developers

Wayland was founded by the X developers who wanted to call it X12 but realized that people would freak the hell out if they fixed it the way that it needed fixing, based on their experience with X11.

Do you mean Kristian Høgsberg? I'm curious about how they needed to fix X11 and Wayland being the incremental successor X12, would you elaborate? Got a link?

Comment Re:What kind of pain will it work on? (Score 5, Interesting) 144

Does it only work for chronic pain or something in particular? I've tried to use it in place of aspirin to little or no effect.

I snapped an achilles tendon and to control pain after the surgery, I polished off over a litre of morphine and had been using codine for several months. I had reached a level of use where the doctor told me I was facing liver or kidney failure if he proscribed any more and he suggested THC as an alternative to the pain killers.

It worked while I healed, during rehabilitation and it took two years to be able to walk again. Six months to recover from the surgery and eighteen months learning to walk again all of which required some really painful physiotherapy. It took another four years before I could sit in a car longer than 20 minutes. I used and recognised signs of THC dependency as simply getting tired of consuming it. So it was a lot easier to overcome, reduce and tolerate the withdrawal symptoms of the THC compared to being on morphine or codine for that long which made me feel like a zombie unable to do much.

To compare physical amounts, 25 cigarettes of tobacco as weed would take me about a week to consume to deal with chronic pain. The same amount may take over a month to consume recreationally as I am physically unable to consume that much weed.

My experiences were that you won't get high or euphoric when you use THC as a painkiller, however the sensation of pain will reduce and that helps you to relax. It also helped maintain my appetite when I didn't feel like eating. I also suffered several spinal injuries and found pain controling that using THC left me more alert and functional compared to opiate based pain killers.

For me pain control with THC help me through significant physical trauma, several times.

Comment THE OPPORTUNITY TO ADVANCE POWER TECHNOLOGY (Score 1) 222

The core of the argument is sound though. It costs ~$500k to put up a 100kW wind turbine. With energy at about 12c/kWh, each hour at full power would generate only $12 and would thus break even after 5 years of full-time, full-power wind

You are talking about the full site establishment costs there. Energetic costs to host subsequent generations of turbines at each site become the cost of replacing the wind turbine with a crane.

however the largest turbines catch wind only 20% of the time and are only 30-45% efficient, smaller ones even less. So you're looking at 50 years before they break even.

This is why "measures" like "Capacity Factor" are bogus measures, every power generation techniques has characteristic. For example, nuclear reactors only us 0.3% of the energy in the fuel so they are relatively inefficient too. Inavailability of a reactor to produce power due to maintenance or some other reason that keeps them offline. Once the reactor is available there is also the utilization of the power it produces, they may produce a good base of power, but that doesn't mean a nuclear reactor can follow demand that well.

That is off course if they never needed maintenance, these turbines are specced for 20-30years of service WITH maintenance but most of them last only half that long.

That is a good platform for the incremental advancement of wind turbine technology. You cannot do that sort of advancement with operational nuclear reactor technology until you build a new reactor.

Wind power is a loss at this point in time unless we jack the price of energy like Germany does, we need way lower costs and way higher efficiencies but for that we need rare earth magnets and the like.

Well it would be devestaing if wind power melted down and spread radionuclides into the environment however it would seem the worst they do is overspeed and catch fire. I see as more wind power installations are deployed the grid itself will change in the way it responds to availability, demand and utilization.

Solar is better (less maintenance) but it still doesn't compare to a well-maintained nuclear plant or other forms of clean energy.

It would be difficult to imagine a large scale solar plant having more maintenance issues that a nuclear power plant.

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